考虑玄武岩矿物细观结构的三点弯断裂近场动力学研究

Peridynamics of Three-point Bending Fracture Considering Mesostructure of Basalt Minerals

为研究岩石细观结构对其内部微裂纹萌生、扩展和贯通的影响,基于近场动力学理论从细观尺度出发,建立了能够反映岩石细观结构的数值模型,研究了玄武岩的三点弯断裂行为。首先,研究了双材料杆和含夹杂二维平板问题,并与有限元方法进行对比,验证了数值算法的准确性。然后,利用随机序列方法和Python语言将岩石的细观结构纳入数值模型,建立了能够反映玄武岩细观结构特征的细观近场动力学模型。最后,通过与玄武岩三点弯实验对比分析,研究了不同偏置缺口玄武岩的三点弯细观断裂行为。研究结果表明,建立的细观近场动力学模型可以很好地预测玄武岩的宏观力学行为,以及其内部微裂纹的萌生、扩展和贯通过程,为研究复杂环境下工程岩体的破裂提供了一种有效的数值计算方法。

In order to study the influence of rock mesostructure on the initiation,propagation and penetration of internal microcracks,a numerical model that can reflect the meso-structure of rock is established based on the peridynamics theory from the mesoscale,and the three-point bending fracture behavior of basalt is studied.Firstly,the problem of bi-material rod and two-dimensional flat plate with inclusion is studied,and the finite element method is compared to verify the accuracy of the numerical algorithm.Then,the random sequence method and Python language are used to incorporate the mesostructure of the rock into the numerical model,and a meso-peridynamics model that can reflect the meso-structural characteristics of basalt is established.Finally,through the comparative analysis with the three-point bending experiment of basalt,the three-point bending meso-fracture behavior of different offset notched basalts was studied.The results show that the established meso-peridynamics model can well predict the macroscopic mechanical behavior of basalt,as well as the initiation,expansion and penetration of its internal microcracks,which provides an effective numerical calculation method for studying the fracture of engineering rock mass in complex environments.